Quaternary phosphonium polyphosphates



QUATERNARY PHosPHoNrUM POLYPHOSPHATES Peter William Brett Sennnens, Norton-on-Tees, England, assignor to Imperial Chemical Industries Limited, Loin don, England, a corporation of Great Britain No Drawing. Application April 9, 1956 Serial No. 576,758

Claims priority, application GreatBritain April 20, 1955 6 Claims. ((21. 260-6065) This invention relates to quaternary phosphonium polyphosphate compounds which are new compounds.

According to the present invention, there is provided a quaternary phosphonium polyphosphate salt having (E D k units forming substantially linear groups, each (F5 unit being associated with a' cation, a major pro-' potassium or other cations associated with the (P0 units. These cations may be present as a result of their incomplete substitution in a polyphosphate salt by quaternary phosphonium cations, or they may be deliberately introduced during thepreparation of the compounds of the present invention. In a preferred group of polyphosphate compounds of the present invention at least one of said organic radicals includes at least one alkyl radical having six or more carbon atoms. Such organic radicals include for example octyl, decyl, dodecyl, tetradecyl, cetyl and lauryl, and radicals such as beta-para-tert.-octyl phen'-.

oxyethyl in which the alkyl radical having the required minimum number of carbon atoms forms part of a larger radical which may include other alkyl or aryl radicals, and/or other functional groups. The preferred polyphosphate compounds of the present invention include for example, cetyl tripropyl phosphonium polyphosphate,

didecyl dimethyl phosphonium polyphosphate and tetradecyl phosphonium polyphosphate.

According to a further feature of the present invention new compositions of matter are provided which are suitable for use as boundary lubricants and which comprise one or more of the preferred polyphosphate compounds of this invention dissolved or dispersed in a liquid or solid vehicle which is preferably a lubricant. Suitable vehicles States atent O "ice may be used as insecticides or to give water repellent finishes to glass or textiles.

The preferred polyphosphate compounds of this inven tion provide eifective boundary lubricants of ferrous metals and may be used either alone or in admixture with suitable materials. Boundary'lubrican'ts are effective in lubricating, surfaces, particularly metal surfaces, which are sliding under conditions of heavy loads and/or slow relative sliding speeds, these conditions usually being known as boundary conditions. Under boundary condi tions, surface contact occurs and frictional forces between sliding surfaces are considerable, resulting in wear and even, in extreme cases, in seizure of the sliding parts. The efi'ectiveness of these preferred compounds as boundary lubricants is therefore a most important property. They are efiective boundary lubricants of mild steel surfaces and of austenitic stainless steel surfaces such as austenitic stainless steel shafts in journal bearings.

Potassium polyphosphate for use in the process of the present invention may be prepared by heating potassium dihydrogen orthophosphate at a suitable temperature, for example 650 to 700 C., for a period of preferably about one hour.

Solubilised polyphosphates suitable for .use in the process of the present invention may be produced by any of the following methods:

(a) Powdered potassium polyphosphate may be added to water, and contacted with the sodium salt of a cation exchange resin, such as, for example, the sodium salt of a sulphonated polystyrene or of a sulphonated phenolic resin. The potassium polyphosphate, on treatment in this manner, goes into solution as a sodium-potassium polyphosphate.

(b) Instead of using a sodium'salt of a cation exchange "resin as described in (a), it is possible to use an ammonium salt of a cation exchange resin. On treatment which are lubricants include for example, mineral or vegetable oils or greases, esters of aliphatic dicarboxylic acids, polyalkylene glycols, polymethyl-phenyl siloxanes,

mixtures of substantially completely halogenated aromatic hydrocarbons such as that sold under the British regis tered trademark Florube 1, or any combination of these. The relative proportions of vehicle in these com positions may be varied over a wide range.

' in this manner the potassium polyphosphate goes into solution as ammonium-potassium polyphosphate.

(c) The use of the salt of a cation exchange resin as in (a and (b), has the disadvantage that the resin must either be discarded or regenerated. An alternative method which avoids the use of a cation exchange resin is to allow powdered potassium polyphosphate to stand in contact with a solution of a-sodium salt, for example sodium chloride. The product swells during this treatment, and may be dissolved in water to give a viscous solution suitable for use in the process of the present invention.

(d) Potassium polyphosphate is solubilised on treatment with hydrogen peroxide, for example by adding potassium polyphosphate to hydrogen peroxide. It is necessary to neutralise the hydrogen peroxide, which usually contains a small quantity of acid, prior touse by the addition of a small quantity of alkali.

The solubilised potassium polyphosphate is brought into contact in solution with an aqueous solution ofquaternary phosphonium salt, such as the bromide, for ex ample by mixing with stirring. It is preferred to add the phosphonium salt solution gradually, and to stop when precipitation of the quaternary phosphonium polyphosphate, which comes out of solution during the addition, is complete. The concentrations of the polyphosphate solution and the quaternary phosphonium salt solution are not critical, but it 'is preferred that they should be approximately equal and approximately 1% by weight. The product may then be separated, washed with water and dried.

As an alternative to first solubilising potassium polyphosphate, the products of the present invention may be prepared by bringing powdered potassium polyphosphate into contact with an aqueous solution of quaternary phosphonium salt, for example the bromide. The product swells during this treatment, and may be washed to re- L10: excess quaternary phosphonium salt and potassium ali e.

-The quaternary phosphonium polyphosphatcs of the present invention are in general solids which are insolu-f ble in water, but they may be soluble inorganic solvents such as chloroform.

EXAMPLE -1 120 grams of air driedion exchange resin soldunder the British registered trademark zeo Karb 215 wereactivated into the ammonium form by treatment. with amn P205 85 NH, 0.2 K 0.1

of a 1% aqueous solution of cetyl tripropyl phosphonium bromide. The product was collected in the same way as in Example 1.

EXAMPLE 3 200 mls. of 29% w./v. hydrogen peroxide diluted with 200 mls. of water were neutralised with 2 mls. of normal sodium hydroxide solution, and added to 8 grams of potassium polyphosphate. The mixture was vigorously stirred and after 15 minutes the potassium polyphosphate was completely dissolved. A further 350 mls. of water were added to the solution which then contained 1% by weight of KPO 50 mls. of this solution were treated as in Examples 1 and 2.

Cetyl tripropyl phosphonium polyphosphate was tested as a boundary lubricant in the following way. Coefficients of friction. were measured between 20 and 200 C. on 'a kinetic boundary friction apparatus, the moving surfaces being ofaustenitic stainless steel and moving at a relative speed of 0.08 cm. per second. Measurements were made using no lubricant and using vehicles only as lubricants. Further measurements were made using cetyl tripropyl phosphonium polyphosphate alone as a lubricant, and also in the form of a 5% dispersion by weight in the vehicles tested.

The results obtained are given in the table below.

The dispersions tested were made by mixing the two components by stirring, if necessary with heating to moderate temperatures for a short time.

Coefi'icient of friction between auste'nitic stainless steel surfaces-surface speed 0.08 cm./sec.

Lubricant Coefficient oi friction Percent Poiy- Percent vehicle 20 100 120 140 160 180 200 phosphate 0. O 0. C. C. O. 0.

Nil Nil "1.11 1. 27 1. 24 1. 30 1. 28 1. 25 1. 28 1. 31 Nil 100% M 0.12 0. 12 0. 12 0.12 0.13 0.16 0.19 0. 20 OPP 95% M0 0. 11 0.11 0.09 O. 08 0. 08 0. 08 0.07 0.12 N 11 100% DS 0. 14 0. 15 0. 18 0. 18 0. 19 0. 21 0. 23 0. 23 6% GP? 95% DS -0. 12 0.10 '0. 0.08 0.08 0.07 0.08 0.03 N i] 100% PAG 0. 0. 21 0. 21 0. 0. 19 0; 22 0. 20 0. 23 5% OPP 95% P 0. 14 0. 12 0. 10 0. 09 0. 09 0. 10 0. 12 N11 100% 0 0. 15 0. 15 0. 16 0. 17 0. 19 0. 17 0.20 0. 18 5% OPP 95% X 0. 14 0. 12 0. 10 0. 10 0. 11 0. 11 0. 10 0. 10 Nil 100% FPS 0.20 0.20 0.26 0.43 0.53 0.01 0.87 0.98 5% OPP 95% PPS 0. 16 0.16 0. 21 0.17 0.23 0.23 0. 23 0. 23 100% OPP N 0.00 0. 00 0.00 0.06 0. 05

References:

M0-M1nerai oil, viscosity 350 cs. at 70F.. 12 ca. at 200F.

DS-Di(ethyl hexyl) sebacate. a PAG-Poiyalky1ene glycol, viscosity 61.7 as at 100 F., 11 cs. at 210 F. CXFlorube" 1, (British registered Trademark).

PPS-Polymethyl-phenyl slloxane, viscosity 2500s. at 100 F., 25 cs. at 210 F. OPP-cetyl tripropyl phosphonium polyphosph ate.

EXAMPLE 2 2.5- grams of potassium polyphosphate were, added to mls. of a solution containing sufficient sodiumchloride to give a potassiumzsodium atomic ratio of 1:2. The mixture was slowly stirred for hour, the solution poured'otf and 180 mls. of water added. After rapid agitation, nearly all of the swollen residue passed into solution. A small amount of undissolved material was separated by filtration. 5.0 mls. ofj'thisi solution were treated in the same way as in Example 1 by the addition It will be seen that the vehicl'e-polyphosphate compositions are effective boundary lubricants and even at a concentration as lowas 5%, there is an improvement over the vehicle-used alone which becomes moremarked at higher temperatures. It can further be seen that the effectiveness of the compositions in most cases is maintained over a wide temperature range.

I claim:

1. A quaternary phosphonium polyphosphate salt having (1 6 units forming. substantially linear groups, each (1 69* unit being-associated with a cation, the major proportion of such cations being quaternary phosphonium cations, in each of which the four valences of the phosphorous atom are attached to organic radicals selected from the group consistingof alkyl radicals and monocyclic arylo'xyalkyl groups and themino'r proportion of such cationsbeing selected from the group-consisting of hydrogen; ammonium, sodium and potassium ions 2. A quaternary phosphonium polyphosphate' salt as set forth in claim 1 in which the organic radical is a betaquaternary phosphonium cations are 'tetradecyl phosphonip-tertiaryoctylphenoxyethyl radical. um groups.

3. A compound according to claim 1 in which at least one of said organic radicals includes at least one alkyl Refer Cited in the file of this patent radical having at least six carbon atoms. 5

4. A compound according to claim 1 in which the UNITED STATES PATENTS said quaternary 'phosphonium cations are cetyl tripropyl 2,220,851 Schreiber Nov. 5, 1940 phosphonium groups. 2,360,623 Rosen Oct. 17, 1944 5. A compound according to claim 1 in which the said 2,414,263 Kemp Jan. 14, 1947 quaternary phosphonium cations are didecyl dimethyl 10 2,446,647 Stern Apr. 5,1949 phosphonium groups. I 2,703,814 Dye Mar. 8, 1955 16. A compound according to claim 1 in which the said 2,745,877 Bindler May 15, 1956 

1. A QUATERNARY PHOSPHONIUM POLYPHOSPHATE SALT HAVING (PO3)- UNITS FORMING SUBSTANTIALLY LINEAR GROUPS, EACH (PO3)- UNIT BEING ASSOCIATED WITH A CATION, THE MAJOR PROPORTION OF SUCH CATIONS BEING QUATERNARY PHOSPHONIUM CATIONS, IN EACH OF WHICH THE FOUR VALENCIES OF THE PHOSPHOROUS ATOM ARE ATTACHED TO ORGANIC RADICALS SELECTED FROM THE GROUP CONSISTING OF ALKYL RADICALS AND MONOCYCLIC ARYLOXYALKYL GROUPS AND THE MINOR PROPORTION OF SUCH CATIONS BEING SELECTED FROM THE GROUP CONSISTING OF HYDROGEN, AMMONIUM, SODIUM AND POTASSIUM IONS. 